Endoscopic instrument assembly for fastening tissue

ABSTRACT

An endoscopic instrument assembly for fastening bodily tissue is disclosed. The assembly includes a surgical instrument for insertion into and withdrawal from the passageway of a cannula. The instrument has a tube with a neckdown region between the proximal and distal ends of the tube. The proximal and distal ends of the tube have a diameter greater than the neckdown region. When the instrument is inserted into the passageway of the cannula, the radial clearance at the neckdown region of the tube is greater than the clearance at the tube distal end. The instrument includes a suture filament for fastening the tissue, and a needle attached to the distal end of the filament. When the instrument is inserted through the cannula, the filament has a length where the needle lies adjacent the neckdown region of the tube and is contained within the greater radial clearance offered by the neckdown region. Consequently, the drag force observed during insertion of the instrument through the cannula because of frictional contact between the needle and the inner wall of the cannula is significantly lessened or avoided altogether. This reduction in drag force can be accomplished without sacrificing other important design features of the surgical instrument.

This is a continuation-in-part of U.S. Ser. No. 08/882,506, filed Jun.25, 1997, now U.S. Pat. No. 5,814,069, which is a continuation-in-partof U.S. Ser. No. 08/841,962, filed Apr. 8, 1997, now U.S. Pat. No.5,749,898, each of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

This invention relates to an assembly for facilitating the placement ofa surgical knot made from a suture filament. In particular, theinvention relates to such an assembly which is particularly adapted fordeployment of the knot during minimally invasive surgical procedureswhere access to the surgical site is limited.

A mainstay of surgical practice has been and will continue to be theformation and placement of surgical knots from suture filament to fastentissue during an operative procedure. Numerous surgical knots have beendeveloped over an appreciable period of time, and the art of forming andtying knots for surgical applications is a critical skill which asurgeon must possess to perform an operation safely and efficiently.Accordingly, the art is extensively developed. See, for example, TissueApproximation in Endoscopic Surgery, Alfred Cuschieri, Zoltan Szabo,Times Mirror International Publishers, 1995, which describes numeroussurgical knots made from suture filament to facilitate the approximationof tissue during surgery.

The art of surgical knots is also well represented in the patentliterature. U.S. Pat. No. 2,012,776 discloses a surgical instrument forfacilitating the placement of various forms of slip knots made fromsurgical filament. The inventor named on the '776 patent, H. A. Roeder,developed the "Roeder Knot" which is a surgical knot which is frequentlyused in practice today. More recently, U.S. Pat. No. 5,573,286 disclosesa surgical knot of suture strand particularly adapted for orthopedicapplications. The preferred embodiment described in the '286 patent isdirected to tying the knot to a bone.

Early on, it was recognized that the deployment and placement ofsurgical knots within a remotely accessible surgical site could bedifficult, cumbersome and often unreliable. Accordingly, instrumentationwas developed to facilitate the placement of knots in remote locations.Cleverly, a pre-tied knotted loop of suture was often used to reduce thenumber of steps required to form the tightened knot. For example, U.S.Pat. Nos. 2,566,625 and 3,090,386 describe surgical devices which areadapted to support a pre-tied knotted loop of suture for suturing orligating tissue, particularly during procedures where the tissue desiredto be manipulated is difficult to access.

More recently, instrumentation has been developed for facilitating theplacement of knots particularly during minimally invasive surgicalprocedures. In particular, U.S. Pat. No. 5,320,629 discloses theformation of a pre-tied knotted loop of suture, and the placement of thepre-tied knotted loop on a surgical device for facilitating thetightening of the loop to approximate tissue during endoscopic surgicalprocedures. German Patent No. 912619 also discloses a device similar tothat disclosed in the '629 patent.

Although the art of surgical knots is well developed, and surgicaldevices for facilitating the placement of tightened knots from apre-tied knotted loop of suture have also been developed for applicationat remote surgical sites, there are problems which still need to beaddressed. In particular, in those surgical procedures where access tothe site is limited, for example during minimally invasive proceduressuch as endoscopic surgical procedures, the knots can be difficult todeploy. Frequently, the knots which can be deployed are routinely slipknots having poor knot security. If knot security is poor, then theapproximated tissue may not be held for a sufficient period of time topromote adequate wound healing. Additionally, during minimally invasiveprocedures, the pre-tied knotted loops of suture which have beendescribed in the prior art devices can be difficult to efficientlytighten for final deployment.

Therefore, in minimally invasive surgical procedures where access to thesurgical site is limited, what is needed is an assembly for facilitatingthe formation of a surgical knot. The assembly should be relativelysimple in construction and should be compatible with a partially tiedsurgical knot. The assembly should facilitate the conversion of thepartially tied knot into a fully formed knot which can provide aconsistently strong knot security each time the knot is placed to enableeven an inexperienced surgeon to confidently and efficiently place asecure suture knot. Additionally, it would be desirable if it werepossible to easily retrofit the assembly onto various surgicalinstruments, particularly endoscopic instruments, for ease of use of theassembly to place surgical knots. Finally, it would be helpful if itwere possible to reload the assembly with a second partially tied knotfollowing deployment of the first knot so that the assembly can be usedto place multiple knots.

In addition, what is needed is a device to facilitate the loading of asuture cartridge assembly onto a surgical instrument. Specifically, whatwould advance the state of the surgical art would be a device which aidsthe surgeon to load the assembly onto a surgical instrument fordeploying a surgical knot from the suture filament contained in theassembly, and to easily reload the instrument with a second suturecartridge assembly after the first spent assembly has been removed fromthe instrument. It would also be advantageous if such a device could bedesigned to avoid the need for the user to handle a needle when attachedto the filament and to be a suitable container for shipping and storageof the suture cartridge when used in conjunction with the otherpackaging materials.

Further, in recognition of the need to facilitate knot tyingendoscopically, what is also needed is an endoscopic instrument assemblywhich is capable of delivering the partially tied knot to the targetedanatomical structure within the internal body cavity during theendoscopic procedure. To that end, what is needed is an assembly whichincludes the knot tying instrument for efficient delivery through atrocar cannula. Specifically, it would be desirable if the suturefilament and needle of the surgical knot tying instrument could bereadily delivered through the cannula, without sacrificing or overlycomplicating the suture cartridge assembly or the resistance of theinstrument to bending or tortial stresses incurred during use.

SUMMARY OF THE INVENTION

The invention is an endoscopic instrument assembly for fastening bodilytissue within an anatomical body cavity. The assembly comprises acannula which has an inner wall and a passageway through it, and asurgical instrument. The surgical instrument can be inserted into andwithdrawn from the passageway of the cannula. The instrument has a tubeand a suture filament for fastening the bodily tissue.

The tube of the surgical instrument has proximal and distal ends, aswell as a neckdown region between the proximal and distal ends of thetube. The proximal and distal ends of the tube have a diameter greaterthan the neckdown region. When the instrument is inserted into thepassageway of the cannula, the distal end of the tube and the inner wallof the cannula define a first radial clearance. In addition, theneckdown region of the tube and the inner wall of the cannula define asecond radial clearance. The second radial clearance is greater than thefirst radial clearance.

The suture filament for fastening the bodily tissue is fixed to thesurgical instrument adjacent the distal end of the tube. The suturefilament has a needle at a distal end of the filament for penetratingthe bodily tissue desired to be fastened. The suture filament has adistal filament portion extending from the distal end of the tube to theneedle.

When the surgical instrument is inserted into the passageway of thecannula, the distal filament portion of the suture filament has a lengthsuch that the needle is located adjacent the neckdown region of the tubeand contained within the second radial clearance.

Advantageously, the second radial clearance defined by the neckdownregion of the tube and the inner wall of the cannula providessignificantly greater clearance for the placement of the needle neededto penetrate the targeted bodily tissue. Consequently, the frictionalcontact between the needle, including the sharp tip of the needle, andthe inner wall of the cannula, can be significantly lessened or avoidedaltogether. This reduction in the drag force enhances the ease withwhich the surgical instrument can be inserted into and withdrawn fromthe passageway of the cannula, and lessens the risk of causing damage tothe needle or its sharp point.

In a particularly preferred embodiment of the invention, the distal endof the tube has a cartridge carrier, and a suture cartridge containingthe suture filament including a partially tied knot is received in thecartridge carrier. In this preferred embodiment, the advantagesattendant with the neckdown region of the tube, including the enhancedclearance provided by the second radial clearance, are realized withoutthe need to significantly reduce the size of the suture cartridge loadedinto the cartridge carrier. Therefore, the manufacturability of thecartridge, and its handling in the operating arena by the ultimate enduser, do not need to be sacrificed. Additionally, since the proximal endof the tube has a diameter greater than that of the neckdown region, theproximal end of the tube can still provide the needed resistance tobending and torsional stresses caused during use of the instrument todeploy the knot.

The endoscopic instrument assembly of this invention can be used duringany endoscopic surgical procedure where it is necessary or desirable tofasten bodily tissue using a surgical knot derived from a suturefilament.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-6 are perspective views illustrating the sequence of steps forforming a partially tied knot from a length of suture filament.

FIGS. 7-8 are perspective views of the steps to convert the partiallytied knot depicted in FIG. 6 into a non-slip surgical knot.

FIGS. 9-10 are perspective views illustrating the formation of thepartially tied knot of FIG. 6, which includes a surgical needle attachedto the suture filament, about a core tube.

FIG. 11 is an exploded perspective view illustrating the partially tiedknot of FIG. 6 formed about the core tube depicted in FIGS. 9-10, incombination with a suture cartridge.

FIG. 12 is a perspective view in assembly of the combination depicted inFIG. 11, where the suture cartridge has a cartridge top.

FIG. 13 is a section view of the assembly depicted in FIG. 12 takenalong line 13--13 of that Figure.

FIGS. 14-15 are section views of the assembly depicted in FIG. 13,including a fragmentary section of tissue, illustrating the use of thepartially tied knot to fasten tissue and the steps necessary to form thecompleted non-slip surgical knot to securely fasten the tissue.

FIGS. 16 and 17 are perspective views depicting the formation of adifferent partially tied surgical knot from a length of suture filament.

FIG. 18 is a perspective view of the partially tied knot depicted inFIG. 17 formed about a stripping tube.

FIGS. 19-20 are side elevation views illustrating the use of theassembly depicted in FIG. 18 to form a completed, non-slip surgical knotto fasten tissue.

FIGS. 21-23 illustrate the use of the partially tied knot depicted inFIG. 6 formed about a tapered core tube to fasten tissue when thepartially tied knot is converted to a completed, non-slip surgical knot.

FIG. 24 is a perspective view of a preferred suture cartridge assembly

FIG. 25 is an exploded perspective view illustrating the partially tiedsurgical knot of the preferred suture cartridge assembly wrapped about acore tube and separated from the suture cartridge of the assembly.

FIG. 26 is an exploded perspective view illustrating the initial step ofassembling the suture cartridge assembly of FIGS. 24 and 25 where thesurgical needle attached to the distal end of the suture filament isloaded into the cartridge slot of the suture cartridge.

FIG. 27 is a perspective view illustrating a further step of assemblyfollowing the loading of the core tube into the cartridge slot, wherethe proximal end of the suture filament is secured to a cartridgehousing attached to the suture cartridge.

FIG. 28 is a plan view of the suture cartridge of the preferred suturecartridge assembly of FIG. 24 including the cartridge housing.

FIG. 29 is a left side elevation view of the cartridge of FIG. 28.

FIG. 30 is a bottom view of the cartridge of FIG. 28.

FIG. 31 is a right side elevation view of the cartridge of FIG. 28.

FIG. 32 is a rear or proximal end elevation view of the cartridge ofFIG. 28.

FIG. 33 is an exploded perspective view illustrating the placement ofthe loaded suture cartridge assembly of FIG. 24 into a cartridgecarrier.

FIG. 34 is a bottom view of the grasping jaw of the cartridge assemblyof FIG. 24.

FIG. 35 is a right side elevation view of the jaw of FIG. 34.

FIG. 36 is a proximal end elevation view of the jaw taken along line36--36 of FIG. 35.

FIG. 37 is a perspective view of the cartridge assembly of FIG. 24mounted in a cartridge carrier and used in cooperation with a closuretube of a surgical instrument to grip tissue.

FIG. 38 is a perspective view similar to that of FIG. 37 where thecartridge assembly is used to grip a segment of the suture filament.

FIG. 39 is a perspective view similar to that of FIG. 37 where thecartridge assembly is used to grip a surgical needle.

FIG. 40 is a perspective view of the preferred load assist device ofthis invention in a cooperative relationship with a cartridge carrier ofa surgical instrument.

FIG. 41 is a proximal end view of the load assist device of FIG. 40.

FIG. 42 is an exploded view of the load assist device of FIG. 40illustrating the enclosure of the suture cartridge in the cartridgecasing.

FIG. 43 is an inside elevation view of the base of the cartridge casingillustrating the placement of the suture cartridge including the suturefilament and surgical needle in the base. The cover of the cartridgecasing for the load assist device is shown in phantom line. Thecartridge carrier of the surgical instrument is shown in pre-loadrelationship with the load assist device.

FIG. 44 is a view in side elevation of the interior of the load assistdevice of FIG. 40 as the cartridge carrier makes contact with the suturecartridge inside the cartridge casing.

FIG. 45 is a view in side elevation of the interior of the load assistdevice of FIG. 40 illustrating the suture cartridge having been seatedonto the cartridge carrier of the surgical instrument.

FIG. 46 is a view in side elevation of the interior of the load assistdevice of FIG. 40 illustrating the suture cartridge assembly securedinto the cartridge carrier when a closure tube in the surgicalinstrument is moved forwardly to cover a portion of the suturecartridge.

FIG. 47 is a view in side elevation of the interior of the load assistdevice of FIG. 40 illustrating the partial withdrawal of the loadedcartridge carrier.

FIG. 48 is a view in side elevation of the interior of the load assistdevice of FIG. 40 illustrating the further withdrawal of the loadedcartridge carrier.

FIG. 49 is a view in side elevation of the interior of the load assistdevice of FIG. 40 illustrating the separation of the loaded cartridgecarrier.

FIG. 50 is an exploded, perspective view of the components of the handleassembly for a preferred surgical instrument.

FIG. 51 is a perspective view of the preferred surgical instrument as itmay be configured for packaging and shipping and when not loaded with asuture cartridge assembly.

FIG. 52 is an enlarged, perspective view of the distal portion of thesurgical instrument of FIG. 51.

FIG. 53 is a perspective view of the surgical instrument of FIG. 51 inthe configuration for receiving a suture cartridge assembly.

FIG. 54 is a perspective view of the surgical instrument of FIG. 51 inthe configuration for when the distal portion is loaded with a suturecartridge assembly.

FIG. 55 is a side elevation of the surgical instrument of FIG. 51 shownbeing introduced into an endoscopic opening into the body.

FIG. 56 is a side elevation of the surgical instrument of FIG. 51 afterthe lever has been actuated and the knot has been deployed intoanatomical tissue.

FIG. 57 is a side elevation of the interior of the handle assembly ofthe surgical instrument of FIG. 51 in the configurations depicted inboth FIGS. 51 and 54.

FIG. 58 is a side elevation of the interior of the handle assembly ofthe surgical instrument of FIG. 51 in the load/unload configurationdepicted in FIG. 53.

FIG. 59 is a side elevation of the interior of the handle assembly ofthe surgical instrument of FIG. 51 in the configuration depicted in FIG.55.

FIG. 60 is a side elevation of the interior of the handle assembly ofthe surgical instrument of FIG. 51 in the configuration depicted in FIG.56.

FIG. 61 is a side elevation of the distal portion of the preferredendoscopic instrument assembly of this invention illustrating thesurgical instrument as it is being inserted into the cannula andconsequently into the anatomical cavity, and showing how the attachedneedle is situated adjacent the neckdown region of the tube.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1-6 illustrate how a partially tied surgical knot can be made froma length of suture filament. The partially tied knot thus formed can beused in the practice of the specific embodiments of this inventionillustrated hereinafter. Of course, other partially tied knots can beused in the practice of this invention.

The suture filament 30 shown in FIG. 1 can be composed of any suturematerial currently used or hereafter developed. The suture filament maybe a monofilament suture or a multifilament, braided suture. The suturefilament, regardless of construction, may be non-absorbable orbio-absorbable, depending on the particular application for which thesuture is being used to fasten tissue.

The length of suture filament 30 has proximal and distal ends, 31 and32, respectively. Adjacent the proximal end, there is a proximal length33 of suture filament. Correspondingly, adjacent the distal end of thesuture filament, there is a distal length 34 of the suture filament.

As shown in FIG. 2, a first loop 35 is formed by manipulating the distallength 34 of the suture filament. Now looking at FIG. 3, while theproximal length 33 of the suture filament remains fixed, the distallength is manipulated to form a second loop 36 wrapped generallytransversely around the first loop 35. Third and fourth loops, 37 and38, respectively, are likewise formed about the first loop as depictedin FIG. 4. The second, third and fourth loops are generally parallel toeach other and are oriented generally transversely to the first loop.For purposes of describing this partially tied knot, these loops may bereferred to collectively as the "knot loops". The number of knot loopsmay vary depending on the particular application for which the knot isused. In the illustrated embodiment, the second, third and fourth loopstogether form a common loop core 39 which receives the first loop 35.

Reviewing FIG. 5, the loosely formed knot is tightened by applyingtension on the distal length 34 of the suture filament. In so doing, thesecond, third and fourth loop tighten down on the first loop, and thusthe first loops is securely received in the common loop core.

As depicted in FIG. 6, a tissue-fastening loop 40 can be formed bypassing the distal end 32 and the distal length 34 of the suturefilament through the first loop 35.

To form the knot, the partially tied knot of FIG. 6 is taken, andtension on the proximal length 33 of the suture filament is applied inthe proximal direction as indicated by the arrow in FIG. 7. Tofacilitate forming the knot, the surgeon ideally holds his fingertipsagainst the proximal side of the knot loops while tension is applied tothe proximal length 33 of the suture filament. Alternatively, asdescribed in the embodiments below, an instrument can be used to holdthe knot loops in place. As tension is applied, the first loop 35 beginsto be pulled through the common loop core 39 of the knot. When the firstloop has sufficiently diminished in size from that shown in FIG. 6, itsnares the distal length 34 of the suture filament. With continuingproximal tension on the proximal length of the suture filament, thefirst loop and the distal length of filament are pulled through thecommon loop core 39. When the first loop and distal length of filamentemerge from the fourth loop 38, an audible "clicking" sound may alertthe user that the completed knot has been formed.

Although the partially tied knot illustrated in FIG. 6, often referredto as a "blood" knot, is the preferred partially tied knot forconversion into the fully formed, non-slip knot which is used in thepractice of this invention, other slip knots described in the literaturecan be used. The key characteristic for the acceptability of otherpartially tied knots is a common loop core (exemplified in FIG. 6 ascommon loop core 39) allowing passage of suture filament through thecore. See, for example, The Encyclopedia of Knots and Fancy Ropework, R.Graumont and J. Hensel, Fourth Edition, Cornell Maritime Press. Suitablepartially tied knots are shown in this book as numbers 102, 185, 227 and349 on pages 71, 83, 87 and 102, respectively.

As depicted in FIG. 8, the completed surgical knot is a non-slip knot41. The first loop has been eliminated, and a distal loop 42 positionedadjacent to the fourth loop 38 is formed from a portion of the distallength of the suture filament. The tissue loop 40, which is used tofasten tissue, consequently becomes rigidly fixed and secure. Tensionapplied to the loop 40 due to the tendency of the fastened tissue toexpand or pull apart may result beneficially in further tightening ofthe non-slip knot.

Referring to FIGS. 9 and 10, there is shown the formation of thepartially tied knot depicted in FIGS. 1-6, formed about a core tube 43.The core tube facilitates the placement of the partially tied knotadjacent tissue desired to be fastened, as well as the conversion of thepartially tied knot into the completed non-slip knot shown in FIG. 8.The core tube has proximal and distal ends, 44 and 45, respectively. Asurgical needle 46 is attached to the distal end 32 of the surgicalfilament. The proximal length 33 of the filament is passed through thecore tube. The length of suture filament exceeds the length of the coretube so that the proximal length of the suture filament may extend fromthe proximal end 44 of the core tube. Additionally, a sufficient amountof suture filament represented by its distal length 34 exits the distalend of the core tube so that it is possible to form the partially tiedknot about the distal end 45 of the core tube. The first loop 35 and thesubsequent knot loops represented by the second, third and fourth loops,36, 37 and 38, are formed about the distal end of the core tube. Onceformed, tension is applied to the distal length of the filament totighten the knot loops about the distal end of the core tube.

The partially tightened knot formed about the core tube can be loadedinto a suture cartridge 47 as illustrated in FIG. 11. The suturecartridge has an elongated body 48. It also has top and bottom faces 78and 79, respectively. A tube slot 49 for receiving the core tube 43 isembedded in the body of the cartridge between the top and bottom faces.The body also contains a knot recess 50 which has a pair of strippingshoulders 51. Extending from a proximal edge 52 of the tube slot in aproximal direction is a filament slot 53. Correspondingly, extendingfrom a distal edge 54 of the tube slot toward a distal end of thecartridge body is a loop slot 55. The length of the core tube,designated as L₁ in FIG. 11, is less than the length of the tube slot,designated as L₂ in FIG. 11.

When the partially tied knot is formed about the core tube 43, the knotloops are wrapped about the distal end 45 of the core tube. The freeproximal end of the suture filament extends from the proximal end 44 ofthe core tube. The first loop 35 of the partially tied knot extends fromthe distal end of the core tube. When the core tube is loaded into thetube slot 49 of the cartridge body between the top and bottom faces, theknot loops sit inside the knot recess and abut the stripping shouldersof the knot recess. A portion of the proximal length 33 of the suturefilament rests in the filament slot 53 embedded in the body of thecartridge, and the remaining portion of the proximal length of thesuture filament extends from the proximal end of the cartridge body.Correspondingly, the first loop 35 of the partially tied knot and thedistal end 34 of the surgical filament are received in the loop slot 55.A substantial portion of the first loop and the distal length of suturefilament descend from the bottom face 79 of the cartridge body. In itsoriginal position as best illustrated in FIG. 13, the distal end 45 ofthe core tube is adjacent the distal edge 54 of the tube slot. Since thetube slot 49 has a length greater than that of the core tube 43, thecore tube is capable of sliding proximally toward the proximal edge 52of the tube slot. In this position, the knot is trapped in recess 50.The surgeon can then easily manipulate needle 46 and suture filament 34without danger of prematurely deploying the knot.

When the core tube is loaded into the tube slot within the body of thecartridge, a cartridge top 56 can be mounted onto the top face 78 of thecartridge body 48 as shown in FIG. 12. When the cartridge top ismounted, the core tube 43 is fully enclosed within the cartridge.

With the core tube fully enclosed within the suture cartridge, thepartially tied knot wrapped about the core tube can be deployed tofasten desired bodily tissue as illustrated in FIGS. 14-15. The firststep is to position the suture cartridge 47 adjacent bodily tissue 57desired to be fastened. Next, the surgical needle 46 is passed throughthe tissue, and into and through the first loop 35 to form the tissueloop 40. The size of the tissue loop is adjusted to provide theappropriate tension on the opposed tissue sections of the bodily tissue57 desired to be fastened; once the knot is completed to from thenon-slip knot, the tissue loop becomes rigidly fixed and furtheradjustment is unavailable. When the tissue loop 40 is formed andappropriately sized, proximal tension is applied to the proximal length33 of the suture filament in the direction of the arrow as depicted inFIG. 15. The completed knot is formed when sufficient tension is felt orapplied to the proximal length 33.

Advantageously, when tension is applied to the proximal length 33 of thefilament, the first loop is pulled and eventually applies a proximalforce against the distal end 45 of the core tube 43, causing it to slideproximally as shown in FIG. 15. Since the knot loops abut against thestripping shoulders in the knot recess 50, the knot loops remainstationary even though the core tube slides proximally. When the coretube slides to a position where it is adjacent the proximal edge 52 ofthe tube slot 49, the knot loops are stripped from the distal end 45 ofthe core tube. The knot is then ully formed, and the user can remove thecartridge top 56, cut the remaining proximal and distal lengths ofsuture filament, and remove the core tube. Alternatively, the proximaland distal lengths of suture filament can be exposed without removingcartridge top 56 by releasing the tension on proximal length 33 andpulling the cartridge proximally, thus allowing a portion of theproximal and distal lengths of suture filament contained in the coretube 43 to extend distally from recess 50.

The suture cartridge 47 is advantageous because it is readily adaptableto conventional open and endoscopic instruments, and thus readilyfacilitates the formation of the knot. The suture cartridge may bedisposable, or it can be used on multiple patients. When used onmultiple patients, a plurality of disposable core tubes, including thepartially tied knot wrapped about the tube, can be loaded serially intothe suture cartridge to provide for the placement of numerous surgicalknots to fasten tissue using a single suture cartridge.

In another example utilizing the core tube concept, the partially tiedknot is wrapped about the core tube to facilitate the conversion of theknot to the completed, non-slip knot to fasten tissue. This similarembodiment is illustrated in FIGS. 21-23. The one key difference betweenwhat is shown here and that illustrated in FIGS. 9-15 is that the coretube has a tapered distal end. For convenience, the same numbers havebeen used to identify component parts in FIGS. 21-23 as those used inFIGS. 9-15.

Another example of a partially tied surgical knot is illustrated inFIGS. 16-17. The knot is made from a suture filament 58 which has aproximal end 59 and a distal end 60. A surgical needle 61 is attached tothe distal end. The distal end of the filament is manipulated to formthe knot while the proximal end of the filament is held stationary. Acore loop 62, proximal loop 63 and first loop 64 are initially formed.The proximal loop is at a first end 70 of the knot, and the first loopis at an opposite end 71 of the knot. The core loop is situated betweenthe first and opposite ends of the knot. Knot loops, in the preferredembodiment consisting of second, third and fourth loops, 65, 66, and 67,are formed about the proximal loop 63 and the first loop 64. The knotloops together form a common loop core 68. The core loop is positionedwithin the common loop core. When tension is applied to the distal endof the surgical filament while the proximal end of the knot loops issupported, the knot loops are tightened. The knot loops are tightenedabout the first loop, proximal loop and core loop. When tightened, asshown in FIG. 17, the first loop, core loop and proximal loop aresecurely received in the knot loops, and the partially tied knot isformed.

Referring specifically to FIG. 17, the core loop 62 has a free proximalend 69 extending from the common loop core 68 toward the first end 70 ofthe knot. The core loop has a loop end 72 which extends from the commonloop core in an opposite direction toward the opposite end 71 of theknot. The loop end 72 of the core loop 62 is disposed inside the firstloop 64.

The partially tied knot of FIG. 17 can be converted to a completednon-slip knot when axial tension is applied to the proximal loop in theproximal direction while the proximal end of the knot loops issupported. In a manner similar to the deployment of the knot bestillustrated in FIGS. 1-8, the knot is converted when the first loop ispulled through the common loop core to form a distal loop.Advantageously, when tension is applied on the proximal loop, not onlyis the first loop pulled through the common loop core, but also the coreloop is pulled through as well. This provides an advantage because thecore loop creates a sufficient space represented by the common loop coreto enhance the ease of passage of the first loop through the common coreto form the completed knot. Easier passage reduces the amount of tensionwhich is need to be applied to the proximal loop to form the completedknot, and therefore increases the degree of control of the user when theknot is being deployed.

FIGS. 18-20 illustrate the use of the knot depicted in FIG. 17 to fastentissue, where the knot is deployed in combination with a stripping tube73. When the partially tied knot of FIG. 17 is formed, the proximal loop63 is passed through the stripping tube. A portion of the proximal loopextends from a proximal end of the stripping tube. The proximal loop ispassed through the stripping tube until the knot loops abut against thedistal end of the stripping tube. Significantly, the stripping tube hasa tapered distal end 74. The core loop and the first loop extend awayfrom the tapered distal end of the tube. The opening at the distal endof the tube is smaller in diameter than the diameter of the knot loops.Consequently, when tension is applied on the proximal loop in theproximal direction, the knot loops will not pass into the strippingtube.

The conversion of the partially tied knot to the completed knot isperformed in a manner substantially similar to that described inconnection with the conversion of the previously illustrated knotdepicted in FIG. 6.

Referring now to FIGS. 19-20, the stripping tube 73 is positionedadjacent bodily tissue 75 desired to be fastened. The surgical needle 61is drawn through the tissue. A tissue loop 76 is formed when thesurgical needle and distal end of the filament are fed through the firstloop 64. Again, it is important to adjust the size of the tissue loop toprovide for appropriate tensioning of the fastened tissue before theknot is fully deployed. When the desired tissue loop is formed, tensionon the proximal loop 63 is applied in the proximal direction asindicated by the arrow in FIG. 19 to pull the core loop 62 and the firstloop 64 through the common loop core. When the first loop emerges fromthe fourth knot loop 67, the distal loop 77 is formed, and thecompleted, non-slip knot has been created.

The preferred embodiment of a suture cartridge assembly which can beused in the practice of this invention is detailed in FIGS. 24-39. Thepreferred embodiment is a further refinement of the assembly illustratedin FIGS. 11-15 which includes the partially tied surgical knot wrappedabout a core tube, and subsequently loaded into a suture cartridge.

Referring initially to FIGS. 24 and 25, the preferred suture cartridgeassembly 80 includes a suture filament 81 with proximal and distal ends,82 and 83, respectively, configured into a partially tied surgical knot84 wrapped about a core tube 85. The proximal end of the suture filamentextends from a proximal end of the core tube, a first loop 86 of thesurgical filament extends from a distal end of the core tube, and asurgical needle 87 is attached to the distal end of the surgicalfilament.

The suture cartridge has top and bottom faces, 88 and 89, respectively,and a slot 90 for receiving the core tube, including the suture filamentwith its partially tied knot wrapped about the core tube, between thetop and bottom faces of the cartridge. The slot contains a knot recess91 for receiving the partially tied knot of the suture filament, and thepartially tied knot abuts a pair of stripping shoulders 92 within theknot recess. When the core tube is loaded into the slot, a portion ofthe distal end of the suture filament including the surgical needle andthe first loop descend from the bottom face of the cartridge. Acartridge top 93 covers the top face of the suture cartridge, andtherefore encloses the core tube and a portion of the suture filament.

Importantly, a grasping jaw 94 is pivotally attached to the suturecartridge at a pivot pin 95. The grasping jaw faces the cartridge topand is moveable from an open position spaced from the cartridge top to aclosed position adjacent the cartridge top. The grasping jaw is biasedin its open position. A cartridge housing 95 which includes a suturefilament track 96 is also mounted to the proximal end of the suturecartridge.

Referring now to FIGS. 28-32, the details of the suture cartridge andthe cartridge housing integrally mounted to the suture cartridge can beseen. The distal end of the cartridge contains a retaining pin 97 forpermanently attaching the cartridge top 93 to the top face of thecartridge. The retaining pin is "heat-staked" to attach the cartridgetop to the cartridge. Also included at the distal end of the cartridgeis a locating boss 98. There is a pin orifice 99 for receiving the pivotpin for pivotally attaching the grasping jaw to the cartridge. The pivotpin received through the orifice also serves to fix the cartridgehousing to the suture cartridge. A central aperture 100 is contained atthe distal end of the cartridge housing to provide an opening forreceiving the proximal end of the grasping jaw. Also contained withinthe cartridge housing is a torsion spring slot 101 for receiving atorsion spring 102 (see FIGS. 24 and 33) to bias the grasping jaw in itsopen position. The torsion spring has an upper arm 113, a torsion loop114 and a jaw arm 115.

The suture filament track 96 of the cartridge housing includes a ventralchannel 103 which merges into a left side suture groove 104 extendingproximally to the proximal end of the cartridge housing. At the proximalend of the cartridge housing, a pair of lateral filament slots 105 aredisplayed. Continuing from the lateral filament slots, a right sidesuture groove 106 is embedded within the cartridge housing. Thecartridge housing also contains a hook slot 107 surrounded by a pair ofspaced-apart hook tines 108.

Referring now to FIGS. 34-36, the details of the grasping jaw 94 can beseen. The grasping jaw has an inner serrated surface 109 to facilitatethe grasping of tissue, suture filament or the surgical needle. Itcontains a jaw lug 110 including a jaw orifice 111 for receiving thepivot pin 95 for its pivotal mount relative to the suture cartridge. Italso includes a spring arm slot 112 for receiving the torsion spring102. The proximal end of the cartridge top has a spring tab 116. Thespring tab biases and maintains core tube 85 distally during assemblyand knot deployment.

In the preferred embodiment, the suture cartridge assembly is adisposable assembly intended to be discarded after a single patient use.The suture cartridge and the housing are preferably composed of abiocompatible, injection-molded plastic, and the grasping jaw ispreferably made from medical grade stainless steel. Alternatively, thesuture cartridge assembly could be fabricated from a suitable metal in ametal injection molding (MIM) process, which is a conventional formingtechnique adaptable for fabricating conventional staple cartridges forsurgical staplers and cutters.

FIGS. 26 and 27 illustrate how the core tube is mounted into the suturecartridge, and how the proximal end of the suture filament is wrappedabout the periphery of the cartridge housing within the suture filamenttrack. As the core tube is mounted into the slot in the cartridge, thesurgical needle and a portion of the distal end of the suture filamentare passed through the slot, and the partially tied surgical knot ispositioned into the knot recess where the knot abuts against thestripping shoulders and the first loop descends from the bottom face ofthe cartridge. The proximal end of the suture filament is passed throughthe ventral channel of the cartridge housing and is wrapped about theleft side suture groove, lateral suture slots and right side suturegroove of the suture filament track before emerging at an anchor recess117 within the cartridge housing. A knot anchor 118 is tied at theproximal end of the suture filament within the anchor recess to placethe suture filament in a fixed position within the cartridge housing.Also worthy of note in observing FIGS. 26 and 27 are the pair ofretaining slots 119 at a junction between the cartridge housing and thetop face 88 of the suture cartridge for further retaining the cartridge93 top when it is mounted onto the top face of the suture cartridge.

In an especially preferred embodiment, the loaded suture cartridgeassembly which can be used in the practice of this invention is receivedwithin a cartridge carrier 120 of a surgical instrument 121 to furtherfacilitate the deployment of the knot and the grasping of tissue, thesurgical needle or the filament. Referring specifically to FIG. 33, thesuture cartridge including the cartridge housing is loaded into andreceived within the cartridge carrier. The cartridge carrier has a pairof containing walls 122 defining a channel 123 for receiving thecartridge assembly. Each containing wall has a top edge surface 124, anda serrated edge surface 125 at its distal end. The surgical instrumentwhich includes the cartridge carrier for receiving the suture cartridgeadvantageously includes a reciprocating closure tube 126 for urging thejaw to its closed position when the closure tube is reciprocatedforwardly, and to its open position when the closure tube isreciprocated rearwardly. Such an instrument preferably includes a hook127 which is received in the hook slot 107 between the pair of hooktines 108 in the cartridge housing. When the hook is retracted, it pullsthe proximal end of the suture filament within the suture filament track96 of the suture cartridge housing, and the knot is deployed in a mannersubstantially similar to that illustrated in FIGS. 11-15.

Referring now to FIGS. 37-39, it can be observed that when the cartridgeassembly is loaded into the carrier, the serrated edge surfaces of thecontaining walls of the cartridge carrier protrude from the cartridgetop of the suture cartridge, and mesh with the inner serrated surface ofthe grasping jaw when the grasping jaw is in its closed position. In sodoing, the meshing surfaces facilitate the grasping of tissue 128 (FIG.37), the surgical filament 81 (FIG. 38) and the surgical needle 87 (FIG.39). The suture cartridge assembly of this invention thereforefacilitates not only the deployment of a fully formed knot from apartially formed knot, but also the manipulation of tissue or the suturefilament including the surgical needle which is so important during thesurgical procedure to easily place the knot.

The load assist device of this invention, and the manner in which acartridge carrier on a surgical instrument can be loaded with a suturecartridge contained in the load assist device, are illustrated in FIGS.40-49.

Referring initially to FIGS. 40-42, the details of the load assistdevice can be seen. The load assist device 130 has a rigid andtransparent cartridge casing 131, for ease of handling and to readilyobserve the contents within the casing when the cartridge carrier of thesurgical instrument is loaded with the suture cartridge and removed fromthe transparent casing. The casing consists of a base 132 and a topcover 133 facing the base. The top cover is releasably attached to thebase. The cover has distal and proximal pins, 134 and 135, respectively,which are received in corresponding distal and proximal bosses, 136 and137, on the base of the casing. To further secure the top cover to thebase, a lower boss 138 on the base receives a corresponding lower pin(not shown) extending from the top cover, and a casing support rib 139also extends from the top cover and frictionally engages the base.

The cavity between the base and the top cover of the cartridge casingdefines a cartridge storage space 140. The cartridge storage spaceincludes a proximal retainer 141, a distal retainer 142 spaced from theproximal retainer, and a jaw retaining ledge 143 between the proximaland distal retainers. The cartridge storage space receives and securesthe suture cartridge within the cartridge casing of the load assistdevice.

The base and top cover of the cartridge casing also define a carrieraperture 144 for enabling the insertion and withdrawal of a cartridgecarrier of a surgical instrument for deploying a knot during a surgicalprocedure from the suture filament contained in the cartridge. Aninterior carrier channel 145 provides a passageway between the carrieraperture and the cartridge storage space so that when the cartridgecarrier of the instrument is inserted through the aperture, it can passthrough the channel until it enters the cartridge storage space for theloading of the cartridge onto the carrier. The channel is bounded by abase support ledge 146 extending from the base, and a cover support rib147 extending from the top cover in a mutually opposed relationship tothe base support ledge. A sloped inlet ramp 148 is also provided tofurther facilitate the insertion and withdrawal of the cartridge carrierof the instrument. The sloped inlet ramp extends from the carrieraperture to the carrier channel.

The base 132 of the cartridge casing contains a pad 149 upon which thesuture filament of the suture cartridge is placed. The top cover has asuture retainer 150 for retaining the suture filament of the suturecartridge in a fixed position on the pad when the top cover is securedonto the base. In a similar fashion, the top cover has a needle retainer151 for retaining the surgical needle attached to the suture filament ofthe suture cartridge on the pad when the top cover is placed on the baseof the cartridge casing.

The cartridge storage space 140 within the cartridge casing of loadassist device receives a suture cartridge 152. The suture cartridgecontains a surgical filament 153 configured into a partially tied knotwith a first loop 154, and a surgical needle 155 attached to a distalend of the surgical filament. The suture cartridge has a cartridge top156, and a jaw 157 facing the cartridge top. The jaw is pivotallymovable at a pivot pin 158 from an open position spaced from thecartridge top to a closed position adjacent the cartridge top. The jawis normally biased in its open position.

The first loop 154 and the surgical filament 153 are held within theassembly as depicted in FIG. 42 on the central plane offset midwaybetween the external faces of the base 132 and cover 133. Soconstrained, the loop 154 and filament 153 do not become tangled orpinched during the loading of the suture cartridge 152 into thecartridge carrier.

The preferred suture cartridge in the practice of this invention is theassembly depicted in FIGS. 24-39. The suture cartridge 152 is situatedin the cartridge storage space so that a proximal end of the suturecartridge sits on the proximal retainer 141. A distal end of the suturecartridge sits on the distal retainer 142, and the jaw 157 is retainedagainst the jaw retaining ledge 143. In order to firmly secure thesuture cartridge in the cartridge storage space, the spacing between thedistal retainer and the jaw retaining ledge is such that the jaw isoriented in a position between its open and closed positions. In thismanner, the biasing action of the jaw against the jaw retaining ledgehelps to firmly plant the suture cartridge within the cartridge storagespace. It is also noteworthy that the suture cartridge within thecartridge storage space is sloped downwardly from the cartridge proximalend to the cartridge distal end. The assembly depicted in FIG. 42 may bepackaged and sterilized using conventional techniques such as gammairradiation or ethylene oxide exposure.

A surgical instrument 159 is used in cooperation with the load assistdevice for loading the suture cartridge from the cartridge casing ontothe instrument for subsequent deployment of a knot from the suturefilament contained in the suture cartridge. The surgical instrument canbe a conventional open instrument or an endoscopic instrument adaptedfor minimally invasive surgery. Preferably, the instrument is anendoscopic surgical instrument. Advantageously, it has a cartridgecarrier 160 configured for insertion and withdrawal into and out of thecarrier aperture of the cartridge casing, and passage through thecarrier channel to the cartridge storage space. Of course, it must alsobe configured to receive the suture cartridge from the cartridge storagespace. Preferably, the surgical instrument has a closure tube 161movable from a retracted position to an extended position for openingand closing the jaw relative to the cartridge top of the suturecartridge.

Referring now to FIGS. 43-49, there is shown the sequence of steps forloading the cartridge carrier of the surgical instrument with the suturecartridge encased in the cartridge storage space of the cartridge casingof the load assist device. In FIG. 43, the cartridge carrier is orientedfor insertion into the carrier aperture and passage through the carrierchannel. In FIG. 44, the cartridge carrier has been inserted into thecarrier aperture, and is passed through the carrier channel in a loadingdirection indicated by the arrow until it has made contact with thesuture cartridge within the cartridge storage space of the cartridgecasing. As a result of the sloped orientation of the suture cartridge,the cartridge carrier contacts the suture cartridge at a pointintermediate between the proximal and distal ends of the suturecartridge. Referring now to FIG. 45, the carrier is moved distally inthe cartridge storage space, causing the suture cartridge to bedislodged from the distal and proximal retainers in the cartridgestorage space. The dislodgment of the suture cartridge from the distaland proximal retainers, in combination with the movement of thecartridge carrier distally within the cartridge storage space, causesthe suture cartridge to be received in the cartridge carrier of theinstrument. As the suture cartridge is loaded into the cartridge carrierwhen the cartridge carrier is moved distally, the closure tube of thesurgical instrument is maintained in its retracted position. It is alsonoteworthy that because of the slight pressure exerted on the suturefilament and surgical needle sitting on the pad from the suture andneedle retainers of the top cover, there is no interfering movement ofthe suture filament and needle during loading operation. In FIG. 46,once the cartridge carrier of the instrument is loaded with the suturecartridge, the closure tube of the instrument is moved from itsretracted position to its forward position, thus securing the suturecartridge in the cartridge carrier of the instrument.

Observing specifically FIGS. 47-49, the loaded cartridge carrier of theinstrument is removed from the cartridge casing of the load assistdevice. It is removed simply by withdrawing the cartridge carrier fromthe cartridge storage space, carrier channel and carrier aperture of thecartridge casing in an unloading direction as indicated by the arrow inFIG. 47.

Advantageously, there is a small gap between the base ledge 146 andcover support rib 147 bounding the interior carrier channel within thecartridge casing so that the suture filament and surgical needle canfreely pass out of the cartridge casing (See FIG. 41 to see the gap).Likewise, the pressure which the suture and needle retainers exert onthe suture filament and needle sitting on the pad within the base of thecartridge casing is minimal so that the filament and needle can readilypass out of the cartridge casing.

Once the surgical instrument is used to deploy a knot from the suturefilament contained in the surgical cartridge which has been loaded intothe cartridge carrier of the instrument, the surgeon or operating roomassistant can unload the spent cartridge and dispose of it. Ifadditional surgical knots need to be deployed, the surgeon or operatingroom assistant need only procure another load assist device of thisinvention to facilitate the loading of a second suture cartridge ontothe cartridge carrier of the instrument.

FIGS. 50-60 show a surgical instrument 121 which is the preferredembodiment of this invention. Referring first to FIG. 51, the handleassembly 300 of the surgical instrument includes a grip 192 having aproximal end 193 and a distal end 194, a trigger 180, a lever 220, aleft and a right release button 240 and 238 respectively, one on eachside of the grip 192 (see FIG. 50), and a trigger latch 281. The closuretube 126 is attached to the proximal end of the grip, and is constrainedto slide longitudinally within the grip as controlled by the actuationof the trigger 180. This function allows the loading and unloading ofthe suture cartridge assembly 80 (see FIG. 24) according to the stepsdepicted in FIGS. 43-49 and the opening and closing of the jaw 94 asdepicted in FIGS. 37-39. The actuation of the lever 220 causes thedeployment of the partially tied knot by pulling axially the proximalfilament 33 of the suture thread as depicted in FIGS. 15, 19, and 23,resulting in a completed knot as shown in FIG. 8. The left and rightrelease buttons 240 and 238, allow upon simultaneous actuation, theopening of the trigger 180 in order to load and unload the suturecartridge assembly. The trigger latch 281 holds the trigger against thegrip after the full actuation of the trigger, and releases the triggerfrom the grip after the subsequent, full actuation of the trigger.

FIGS. 51-56 depict the intended sequence of operation of the surgicalinstrument 121 and are described next. Turning again to FIG. 51, theinstrument is shown in a configuration as it may be received prior toinitial usage. As can be seen in FIG. 52 which correlates with FIG. 51,the cartridge carrier 120 is empty and the distal end of closure tube126 is positioned longitudinally about halfway between its most distaland most proximal position, hereinafter referred to as the middleposition. FIG. 53 depicts the surgical instrument in the load/unloadconfiguration. The left and right release buttons 240 and 238 have beendepressed simultaneously, and the trigger 180 has sprung open to theposition shown, in turn, causing the closure tube 126 to retract in theproximal direction. The suture cartridge assembly 80 is shown ready forplacement into the cartridge carrier 120, and the sequence depicted inFIGS. 43-45 using the load assist device 130 would take place next. InFIG. 54, the trigger 180 has been actuated to the middle position asshown and the closure tube 126 has moved distally to its middle positionas depicted in FIG. 53. The suture cartridge assembly 80 is now capturedin the cartridge carrier 120 and the instrument containing the cartridgemay be withdrawn from the load assist device. The next step in the useof the instrument is to introduce the distal end into the anatomicalbody cavity as shown in FIG. 55, and since it is necessary for thegrasping jaw 94 to be in its closed position for insertion through anendoscopic cannula 298, the surgeon's assistant may fully close thetrigger 180 until it latches against grip 192 and is held there bytrigger latch 281 before removing the instrument from the load assistdevice and handing it to the surgeon. This loading sequence is depictedin FIG. 46-49. Once the surgeon has introduced the distal portion of theinstrument into the anatomical body cavity through the endoscopiccannula, the full actuation of the trigger will cause the release of thetrigger from the grip, in turn allowing the closure tube 126 to retractproximally and the grasping jaw 94 to open. The surgical instrument maynow be used for the grasping and manipulation of tissue (as in FIG. 37),the suture (as in FIG. 38), or the needle (as in FIG. 39). FIG. 56 showsthe instrument as the knot is being deployed to fasten the tissue 128.The lever 220 has been actuated by the surgeon's thumb or finger in adownward arc until an internal stop is reached to deploy the knot. Thisactuation may be stopped at any point along this arc and the lever willmaintain its position. This feature allows the surgeon to be able tomanipulate and/or inspect the suture and the tissue it's affixed to forproper suture tensioning and placement of the knot. Once the lever 220is fully actuated and the surgeon's thumb or finger is lifted off of it,the lever returns under spring force to the starting position. Theinstrument may then be withdrawn from the anatomical body cavity, withor without the trigger 180 in the closed position, and be readied forloading of a new suture cartridge assembly.

FIG. 50 is an exploded, perspective view of the components of the handleassembly 300 together with the closure tube 126. The outer shell of thegrip 192 consists of a left grip cover 190 and a right grip cover 200,both made preferably of a rigid, medical grade plastic such aspolycarbonate. These covers contain a plurality of bosses and ribs tosupport and align the components within. The trigger 180 and the lever220 are supported between the left and right grips to move as describedpreviously. A pinion 210, a rack 270, and a closure coupler 260 may bemade of metal, but are preferably made of various types of injectionmolded, rigid, medical grade plastics. The following components of thehandle assembly 300 may be made of plastics, but are preferably made ofmetal, such as a stainless steel: a base anchor 280, trigger latchspring 282, a leaf spring pawl 284, a lever spring 290, a tube spring230, a tube latch 234, a coupler spring 242, a rack spring 250, a washer252, a retaining ring 254, and a suture pull rod 246.

Still referring to FIG. 50 and also now to FIG. 57, the components ofthe handle assembly 300 are visible and are in the operationalconfiguration corresponding to FIGS. 51 and 54. The trigger 180 is inits middle position and is supported on a pivot boss 184 projecting offright grip cover 200. A trigger fork 182 bears against a left and aright push arm 262 and 263, respectively, of closure coupler 260 whichis attached to closure tube 126 by a flange 171 (see FIG. 50) insertedin a coupler recess 264 (see FIG. 50). Coupler spring 242 is compressedbetween the flange and the proximal end of coupler recess 264 so thatlongitudinal force transmitted from the coupler to the closure tube islimited by the spring rate of the coupler spring. This is to insure thatan excessive force is not applied to the jaw 157 by the distal end ofthe closure tube when the surgeon is attempting to grasp tissue oranother object which does not permit the jaw to close fully. Thedescribed trail of components is biased in the proximal direction by apartially compressed tube spring 230 which is captured on the proximalend of closure tube 126. The tube spring pushes off of the inside wallof the grip proximal end 193. Closure coupler 260 is held in its middle,longitudinal position by tube latch 234 and they are attached togetherby three coupler posts 261 pressed into three holes 235 of the tubelatch 234 (see FIG. 50). Tube latch 234 is sprung open transversely sothat a tube latch right end 232 engages with a right latch rib 198projecting off right grip cover 200, and similarly, a tube latch leftend 233 engages with a mirrored left latch rib (not shown) in left gripcover 190. Right and left release buttons, 238 and 240, are positionedover right and left tube latch ends, 232 and 233 respectively. Releasebuttons 238 and 240 are joined together in a "wishbone" manner to a"dovetail-shaped" button anchor 239 which inserts into a right buttonretainer 195 and a mirrored left button retainer (not shown) extendingoff of right and left grip covers, 200 and 190, respectively.

Still referring to FIG. 57, lever 220 is shown in its start position andis supported on a lever pivot boss 222 projecting off right grip cover200. A plurality of lever gear teeth 224 mesh with a plurality of pinionminor gear teeth 213 of pinion 210 which is supported on a pinion pivotboss 212 projecting also off right grip cover 200. A plurality of pinionmajor gear teeth 216 mesh with a plurality of rack gear teeth 272 ofrack 270 which is constrained to move longitudinally between grip coverribs 208 projecting off of left and right grip covers 190 and 200. Leverspring 290 is captured on a proximal end 274 of the rack 270 and ispartially compressed in order to exert an initial separating forcebetween a rack spring chamber proximal end 277 of the rack and twogrounding ribs, 295 and 294, projecting off left and right grip covers190, 200. These grounding ribs are "C-shaped" and extend to the centeraxis of the handle assembly 300. Together they form a hole so thatclearance for the distal end 274 of the rack 270 is provided to allowthe longitudinal movement of the rack in the proximal direction. Theforce of the preloaded lever spring 290 biases the rack in the distaldirection and is transmitted through the drive components described tothe lever 220, thus biasing the lever to remain in its start position.

Referring now to FIG. 58, the handle assembly 300 is shown in theoperational configuration corresponding with FIG. 53 for when thesurgical instrument may be loaded or unloaded with suture cartridgeassembly 80. The trigger 180 is swung fully away from the longitudinalaxis of handle assembly 300 due to the release of the closure coupler260. The surgeon or the surgeon's assistant will have obtained thishandle configuration by simultaneously squeezing the left and rightrelease buttons, 240 and 238, with their thumb and an opposing finger,causing the compression of the tube latch 234, in turn causing the tubelatch 234 to disengage from the right and left latch ribs, 198 and 199.Tube spring 230 exerts a force in the proximal direction on the end ofthe closure coupler 260. The closure coupler 260, the tube latch 234,and the closure tube 126 immediately move proximally, forcing thetrigger 180 to open fully. The trigger opening is limited by the triggerforks 182 hitting against a trigger stop 188 of the covers, 190 and 200.In order for the trigger to open, the user must not be holding thetrigger 180 while the release buttons, 238 and 240, are compressed. Thisfeature specifically is intended to make the retraction of the closuretube 126 a deliberate step while still being one-handed, because it isdesirable to prevent the accidental release of a suture cartridgeassembly 80 into the body cavity.

Once the spent or "fired" suture cartridge assembly is unloaded from thecartridge carrier 120 and a new one is loaded according to the stepsdepicted in FIGS. 43-49, the handle assembly is put into the "ready todeploy" mode as shown in FIG. 59 by squeezing trigger 180 far enough toforce the reengagement of tube latch 234 with the left and right latchribs, 199 and 198, thus repositioning the closure tube 126 into aposition where the suture cartridge assembly 80 is captured in thecartridge carrier 120. When this is achieved, the surgeon may choose toleave the trigger 180 in this position during the actuation of the lever220, or to close the trigger completely and allow it to latch againstthe grip, or to hold the trigger anywhere between the aforementionedpositions.

FIG. 61 depicts the distal portion of the surgical instrument 121 loadedwith suture cartridge assembly 80 as it is being introduced into ananatomical body cavity through an endoscopic cannula 298. Radialclearance 90 between closure tube 126 and inner wall of endoscopiccannula provides space for suture distal filament 83 and suture firstloop 86 to lay alongside closure tube 126 without being damaged. Thelength of distal suture filament 83 is sized so that when it is fullyextended as would occur due to the friction of it on the inside wall ofthe endoscopic cannula 298 as the instrument 121 is pushed distally, theneedle 87 is adjacent neckdown 288 of the closure tube 126, andcontained in radial clearance 801. The neckdown provides a radialclearance 801 greater than radial clearance 90, therefore allowingvarious styles and sizes of curved needles to be introduced into thebody cavity without the needle, specifically the sharp tip of theneedle, being dragged on the inside wall of the cannula. Such draggingcould result in the needle becoming dull or bent and would impair theability of the surgeon to use it to pierce tissue. It is advantageous toneckdown only a portion of closure tube 126 because then the remainingportions may be of the maximum diameter allowable for introductionthrough the endoscopic cannula. Therefore, for example, the size of thevery intricate, suture cartridge assembly 80 can be maximized for easiermanufacture and handling by the user, as well as for having greatergrasping ability, as compared to an assembly which was much smaller toaccommodate a closure tube of smaller diameter. The proximal portion ofthe closure tube 126, having also a greater diameter than the neckdown288, would have an increased resistance to bending and torsionalstresses than if it had a diameter equal to that of the neckdown. It mayalso be appreciated by those skilled in the art that this neckdown neednot only be of a circular cross-section, but may be of various shapes aslong as an increased clearance is created to contain the curved needle.The length of the neckdown may also vary. It is advantageous to providean extra margin of neckdown length to account in variations of thelength of distal suture filament 83, or to account for the suturefilament wrapping around the closure tube 126 during introduction intothe cannula. It should also be appreciated that such a neckdown as shownhas wide application to other types of endoscopic instruments,especially for needleholders and graspers used for the introduction ofsuture and needles when it is desired to maximize the size and/orstrength of the end effectors, to allow for the introduction of needlesof various sizes and shapes.

In FIG. 60, the case is shown for when the lever 220 has been fullyactuated while the trigger 180 has been partially squeezed, but not farenough for trigger hook 186 to latch with a trigger latch spring 282.The downward movement of the lever 220, via the series of gearinteractions already described, has caused the rack 270 to movelongitudinally in the proximal direction and the lever spring 290 tocompress. The rack spring 250 contained in the rack spring chamber 276has likewise moved proximally and transmits a longitudinal force in theproximal direction against washer 252 which abuts against retaining ring254 which is attached to suture pull rod 246. The suture pull rod, inturn, is attached at its distal end to the hook 127 (FIG. 33) whichengages with the proximal end of the suture filament. When the suturepull rod is moved proximally, the knot is deployed in a mannersubstantially similar to that illustrated in FIGS. 11-15. The rackspring 250, therefore, acts as a force-limiting means in that the totalforce transmitted from the rack 270 to the suture pull rod 246 is equalto the pre-loaded force of the rack spring added to the product of thespring rate of the rack spring 250 and the distance it has beencompressed between the rack spring chamber distal end 276 and the washer252. The force-limiting feature of this invention helps to prevent theexcessive tensioning of the suture filament, in which case the filamentwould break before the knot could be fully deployed. The total force istransmitted, however, only when the resistive force of the suture pullrod 246 equals or exceeds the pre-loaded force of the rack spring 250.This resistive force varies primarily with the tension and angle oftensioning of the suture filament distal end 83 (FIG. 56) as applied bythe surgeon during approximation and fastening of the tissue. Themaximum resistive force typically occurs at the instant the knotconverts to a non-slipping knot, as shown in FIGS. 7, 8. It isimportant, therefore, that the rack spring 250 be sized and pre-loadedto transmit a sufficient longitudinal force for knot conversion withoutthe spring collapsing to its solid height, in which case the surgeon mayexert an excessive force to the lever 220 and cause the suture proximalfilament 33 to break. The rack spring 250 should not be sized andpre-loaded to a condition where the force required to compress it anadditional amount nears or exceeds the suture filament tensile strengthbecause then the force-limiting feature could not be used to preventbrealing of the suture filament. During the transmission of the forcesas described, the cartridge carrier 120 is grounded to the grip 192 byattachment to base anchor 280 inserted into a recess 281 on the innerwall of right grip cover 200 (see FIG. 50).

Still referring to FIG. 60, the "T-shaped" leaf spring pawl 284 can beseen mounted to rack 270. During the actuation of the lever 220, thetransverse arms of the leaf spring pawl engage with a plurality of teeth206 molded onto the inner surfaces of the left and right grip covers,190 and 200 (see FIG. 50) so that the rack can maintain its longitudinalposition at numerous discrete points between the starting and stoppingpositions of the lever if the surgeon were to release pressure from thelever. The lever must be fully actuated before the leaf spring pawl hastraveled beyond the end of the molded teeth 206, thereby the pawldisengages from the teeth and springs to a position to allow the returnof the lever to the starting position. The lever must then be releasedby the surgeon so that the rack 270 can move distally due to the forceof the lever spring 290, causing the lever to return to its startposition. This lever holding feature is well-known in the art for itsuse in other surgical devices such as skin staplers.

The handle assembly described is the preferred embodiment, but it may beappreciated that other grip shapes and mechanisms within this assemblyare possible for accomplishing the desired functions. For example, thehandle assembly may have a "pistol grip" or incorporate openings intothe grip and trigger for insertion of the thumb and an opposing finger.In addition, the distal portion of this surgical instrument could bemade to rotate about its longitudinal axis while the handle assembly washeld stationary, with or without a locking mechanism for this rotation.The surgical instrument described can be made to be single patient-usedisposable, reusable, or a combination of the two, depending primarilyon the materials chosen and the method of assembly.

The different embodiments of this invention are representative of thepreferred embodiments of the invention. These embodiments are merelyillustrative. The scope of the invention should not be construed to belimited by these embodiments, or any other particular embodiments whichmay come to mind to those skilled in this art. Instead, the reader mustrefer to the claims which appear below to determine the scope of theinvention.

What is claimed is:
 1. An endoscopic instrument assembly for fasteningbodily tissue within an anatomical body cavity, said assemblycomprising:a) a cannula having an inner wall and a passagewaytherethrough, and b) a surgical instrument for insertion into andwithdrawal from said passageway of said cannula, said instrumenthaving:i) a tube, said tube having proximal and distal ends, and aneckdown region between the proximal and distal ends of said tube, theproximal and distal ends of said tube having a diameter greater thansaid neckdown region, and when said instrument is inserted into saidpassageway of said cannula, the distal end of said tube and said innerwall of said cannula define a first radial clearance, said neckdownregion of said tube and said inner wall of said cannula define a secondradial clearance, and said second radial clearance is greater than saidfirst radial clearance; ii) a suture filament for fastening the bodilytissue, said suture filament fixed to said surgical instrument adjacentthe distal end of said tube, said suture filament having a needle at adistal end thereof for penetrating the bodily tissue desired to befastened, said suture filament having a distal filament portionextending from the distal end of said tube to said needle; wherein whensaid surgical instrument is inserted into said passageway of saidcannula, the distal filament portion of said suture filament has alength such that said needle is located adjacent said neckdown region ofsaid tube and contained within said second radial clearance.
 2. Theassembly of claim 1 wherein said neckdown region of said tube has acircular cross-section.
 3. The assembly of claim 1 wherein said suturefilament is configured into a partially tied knot at a proximal endthereof.
 4. The assembly of claim 3 wherein said partially tied knot isspaced from said neck-down region of said tube and contained within saidfirst radial clearance.
 5. The assembly of claim 4 wherein saidpartially tied knot is housed in a suture cartridge.
 6. The assembly ofclaim 5 wherein the distal end of said tube has a cartridge carrierthereon, and said suture cartridge is received in said cartridgecarrier.
 7. The assembly of claim 1 wherein the needle is a taper pointneedle.
 8. The assembly of claim 7 wherein the needle has a curvedpoint, a curved barrel, and a generally flat midpoint between saidcurved point and barrel.